Top researchers in the field of gravitation present the state-of-the-art topics outlined in this book, ranging from the stability of rotating wormholes solutions supported by ghost scalar fields, modified gravity applied to wormholes, the study of novel semi-classical and nonlinear energy conditions, to the applications of quantum effects and the superluminal version of the warp drive in modified spacetime. Based on Einstein's field equations, this cutting-edge research area explores the more far-fetched theoretical outcomes of General Relativity and relates them to quantum field theory. This includes quantum energy inequalities, flux energy conditions, and wormhole curvature, and sheds light on not just the theoretical physics but also on the possible applications to warp drives and time travel.

This book extensively explores the physical properties and characteristics of these 'exotic spacetimes,' describing in detail the general relativistic geometries that generate closed timelike curves.

Dr. Francisco Lobo is presently a Principal Investigator at the Science Faculty of the University of Lisbon (FCUL), and Thematic Line Leader at the Institute of Astrophysics and Space Sciences (IA). Dr. Lobo completed a PhD degree in Physics at FCUL, in July 2005, with summa cum laude, in the disciplinary field of General Relativity and Cosmology. Research-wise, he has been involved in many mainstream areas of great importance and topicality in modern physics. Several of his publications have received extensive news coverage in the following newspapers and journals: New York Times, International Herald Tribune, Scientific American, National Geographic and New Scientist. Dr. Lobo's impact factor, h, in the scientific community is presently 43. To the present date, he has 115 articles published in high-impact international research journals, 3 papers in press and another 7 under revision, with over 4700 citations (3 papers with 250+, 7 papers with 100+ and 30 with 50+ citations); 7 articles published as book sections; given over 50 presentations (including 3 plenary sessions and 11 invited talks) in international conferences, with the majority published in the proceedings. Dr. Lobo has also been successful in obtaining external funding, and has been involved in several ongoing and recent national/international projects, several of which as Principal Investigator.